Actually in both ears, but only slight in left (noticeable only in complete silence), and much worse in right.
I wondered the whole time, why is it like this, when my audiogram is the same for both ears?
But recently doctor noted that it is NOT the same. There is bigger loss at 1000-1500 Hz on right ear. Never noticed it before.
It is only a few decibels, and it causes such huge difference in tinnitus level!

Anyway - i think that in most cases T is in one ear only, or it is worse at one side. It has maybe something to do with dominant brain hemisphere.
Also I've read somewhere that right/left side for perceiving of T it is different for male and female.